Wednesday, 2 August 2017

Server virtualization has been into trend from a couple of last years and it is a reality that knocks companies, bringing numerous benefits to all who seek the resource savings and a more effective IT management. Furthermore, it is a green technology.

To give a broader view of server virtualization, identified a huge list of advantages and a few disadvantages, which can be compensated by using a cloud provider with recognized market action.

Advantages of Virtual Server:

➥ Facilities to be simplified and space saving.
➥ Centralized management.
➥ Full compatibility with applications.
➥ Greater availability and easier recovery in case of disaster.
➥ Facility for running backups.
➥ Support and maintenance simplified.
➥ Controlled access to sensitive data and intellectual property by keeping them safe inside the data center.
➥ Hardware independence.
➥ Best use of space: the fewer physical devices installed, the greater the availability of space in racks.
➥ The provision of new servers is reduced to a few minutes.
➥ Migrating servers to new hardware transparently.
➥ Saving electrical energy used by servers.
➥ Security – using virtual machines (VM), you can define what is the best environment to run each service with different security requirements, several tools and operating system most suitable for each service. Virtual machines can be isolated and independent of each other, including the host machine. Using a virtual machine for each service, the vulnerability of a service does not affect the other.
➥ Reliability and Availability – the failure of a software does not affect the other services.
➥ The use of a VM as the development environment allows testing at different OSs, and for providing an isolated environment that prevents faults in the configuration and / or implementation, or even viruses, damaging the machine hardware.
➥ The cost reduction is possible using small virtual servers on a more powerful single server.
➥ Adapting to different workloads, which can be treated simply. Typically, virtualization software reallocate hardware resources dynamically between a virtual machine and another.
➥ Load balancing: the whole virtual machine is encapsulated. Thus, it becomes easy to change the virtual machine platform and increase its performance.
➥ Support for legacy applications: when a company decides to migrate to a new operating system, you can keep your old operating system running in a virtual machine, which reduces the cost of migration. It is worth remembering that virtualization can be useful for applications that run on legacy hardware, which is subject to failure and have high maintenance costs. With that hardware virtualization, you can run these applications on newer hardware with lower maintenance costs and higher reliability.
➥ Reduction of personnel costs, power and cooling by using less physical equipment.
➥ Better utilization of hardware – the hardware sharing by virtual machines is reduced to idle equipment.
➥ With virtual machines, you can simulate entire networks, including heterogeneous networks.
➥ You can use operating systems that do not have compatibility with the hardware, using the resources of hardware virtualization. This enables testing and even economy with the purchase of hardware.
➥ Reduced downtime.
➥ Ease of migration environments – prevents reinstallation and reconfiguration of systems to be migrated.

Disadvantages of Virtual Server:

➥ Management – virtual environments need to be instantiated (create instances on virtual machines), monitored, configured and saved. There are products that provide those solutions, but this is the field in which they are the largest investments in the area of virtualization.
➥ Difficulty in direct access to hardware, for example, specific cards or USB devices.
➥ Performance – currently there are no consolidated methods to measure the performance of virtualized environments. To compensate, we introduce an extra layer of software between the operating system and hardware, VMM or hypervisor, which generates a higher processing cost than would have without virtualization. Another important point to emphasize is that no one knows exactly how many virtual machines can be run per processor, without the loss of quality of service.
➥ Great RAM consumption since each virtual machine will occupy a separate area of the same.
Great use of disk space, since it takes all the files for each operating system installed on each virtual machine.

As you can conclude, virtualization has more advantages than disadvantages, because it ends up solving and facilitating many operations. But it is necessary to evaluate all aspects involved in virtualization to avoid crises. For example, the vulnerability or burning a physical host will all virtual machines vulnerable or unavailable, requiring disaster recovery plans. Should also analyze whether the virtual machines have the performance needed for critical operations.